War is among mankind's oldest creations and while many would lament the pain it brings, those who follow the way of iron blood relish in it. They believe war is simply a canvas through which the art of bloodshed paints meaning into life. Just as they believe war give life meaning, so to do they believe that life itself is the best forge for tools of war; birthing bloodshed from bloodshed. Life is fickle and pain in plentiful, and an iron blood monk must relish in this pain. To these monks, true peace is not an absence of pain or conflict, but an accepted abundance of it.

(Full credit to u/Djinngerbread on Reddit for this subclass. They hadn't brought it here)

Iron Blood Technique

Starting when you choose this tradition at 3rd level, you can manipulate the elements in your blood as a means of both offense and defense.

While you are wearing no armor and not wearing a shield, you can choose to have your AC equal 10 + your Constitution modifier + your Wisdom modifier.

In addition, you can manipulate your blood to create claws or spikes to your preference, allowing your unarmed strikes to deal piercing or slashing damage.

 

Scarlet Shield

At 6th level, you gain the ability to focus your ki into your bloodstream, reinforcing your defenses. As a bonus action, you can spend 2 ki points to fortify your blood and skin, gaining a +2 bonus to your AC for up to 1 minute.

You can spend additional ki points to extend the duration of this ability at any point during it's duration, without using any additional action. Each additional ki point you spend increases the ability's duration by 30 seconds. The maximum number of ki points that you can spend total equals half your monk level rounded down.

Crest of Tepes

At 11th level, you gain the ability to lay traps using crests written in your blood. As a bonus action, you can write a crest of blood on the ground in a space you occupy, you cannot place multiple crests in the same five foot space.

If a creature you can see moves into a space within 10 feet of the crest or ends it's turn within that same radius, you can use your reaction to activate the crest, causing a steel blade or spike to extend from the crest at the target. The target must make a Dexterity saving throw, on a failed save the target takes 2d6 piercing damage and has it's movement speed reduced to 0 until the start of it's next turn. On a successful save the creature takes half as much damage and suffers no movement penalties. This feature's damage is magic for the purpose of determining resistance.

You can increase the spike's power by spending ki points when you activate the crest. Each ki point you spend, up to a maximum of 3, increases the damage by 2d6.

Bloodied Berserker

At 17th level, you learn to use your weaponized blood to it's fullest, using the blood that stains you as yet another tool of war.

The first successful attack you make on your turn gains bonus damage equal to 5 + your Constitution modifier if you have no more than half your hit points left.